[X86][SSE] Improvements to byte shift shuffle matching

Since (v)pslldq / (v)psrldq instructions resolve to a single input argument it is useful to match it much earlier than we currently do - this prevents more complicated shuffles (notably insertion into a zero vector) matching before it.

Differential Revision: http://reviews.llvm.org/D6409



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222796 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 33 insertions, 50 deletions

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 63a3009fd82..0833079d573 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8217,6 +8217,11 @@ static SDValue lowerV2I64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                     getV4X86ShuffleImm8ForMask(WidenedMask, DAG)));
   }
 
+  // Try to use byte shift instructions.
+  if (SDValue Shift = lowerVectorShuffleAsByteShift(
+          DL, MVT::v2i64, V1, V2, Mask, DAG))
+    return Shift;
+
   // If we have a single input from V2 insert that into V1 if we can do so
   // cheaply.
   if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1) {
@@ -8243,11 +8248,6 @@ static SDValue lowerV2I64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                                   Subtarget, DAG))
       return Blend;
 
-  // Try to use byte shift instructions.
-  if (SDValue Shift = lowerVectorShuffleAsByteShift(
-          DL, MVT::v2i64, V1, V2, Mask, DAG))
-    return Shift;
-
   // Try to use byte rotation instructions.
   // Its more profitable for pre-SSSE3 to use shuffles/unpacks.
   if (Subtarget->hasSSSE3())
@@ -8508,6 +8508,11 @@ static SDValue lowerV4I32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                        getV4X86ShuffleImm8ForMask(Mask, DAG));
   }
 
+  // Try to use byte shift instructions.
+  if (SDValue Shift = lowerVectorShuffleAsByteShift(
+          DL, MVT::v4i32, V1, V2, Mask, DAG))
+    return Shift;
+
   // There are special ways we can lower some single-element blends.
   if (NumV2Elements == 1)
     if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v4i32, DL, V1, V2,
@@ -8525,11 +8530,6 @@ static SDValue lowerV4I32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                                   Subtarget, DAG))
       return Blend;
 
-  // Try to use byte shift instructions.
-  if (SDValue Shift = lowerVectorShuffleAsByteShift(
-          DL, MVT::v4i32, V1, V2, Mask, DAG))
-    return Shift;
-
   // Try to use byte rotation instructions.
   // Its more profitable for pre-SSSE3 to use shuffles/unpacks.
   if (Subtarget->hasSSSE3())
@@ -8593,17 +8593,17 @@ static SDValue lowerV8I16SingleInputVectorShuffle(
                                                         Mask, Subtarget, DAG))
     return Broadcast;
 
+  // Try to use byte shift instructions.
+  if (SDValue Shift = lowerVectorShuffleAsByteShift(
+          DL, MVT::v8i16, V, V, Mask, DAG))
+    return Shift;
+
   // Use dedicated unpack instructions for masks that match their pattern.
   if (isShuffleEquivalent(Mask, 0, 0, 1, 1, 2, 2, 3, 3))
     return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i16, V, V);
   if (isShuffleEquivalent(Mask, 4, 4, 5, 5, 6, 6, 7, 7))
     return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8i16, V, V);
 
-  // Try to use byte shift instructions.
-  if (SDValue Shift = lowerVectorShuffleAsByteShift(
-          DL, MVT::v8i16, V, V, Mask, DAG))
-    return Shift;
-
   // Try to use byte rotation instructions.
   if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
           DL, MVT::v8i16, V, V, Mask, Subtarget, DAG))
@@ -9210,6 +9210,11 @@ static SDValue lowerV8I16VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
   assert(NumV1Inputs > 0 && "All single-input shuffles should be canonicalized "
                             "to be V1-input shuffles.");
 
+  // Try to use byte shift instructions.
+  if (SDValue Shift = lowerVectorShuffleAsByteShift(
+          DL, MVT::v8i16, V1, V2, Mask, DAG))
+    return Shift;
+
   // There are special ways we can lower some single-element blends.
   if (NumV2Inputs == 1)
     if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v8i16, DL, V1, V2,
@@ -9227,11 +9232,6 @@ static SDValue lowerV8I16VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                                   Subtarget, DAG))
       return Blend;
 
-  // Try to use byte shift instructions.
-  if (SDValue Shift = lowerVectorShuffleAsByteShift(
-          DL, MVT::v8i16, V1, V2, Mask, DAG))
-    return Shift;
-
   // Try to use byte rotation instructions.
   if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
           DL, MVT::v8i16, V1, V2, Mask, Subtarget, DAG))
diff --git a/test/CodeGen/X86/combine-or.ll b/test/CodeGen/X86/combine-or.ll
index 9539eae9d6a..f10092a1378 100644
--- a/test/CodeGen/X86/combine-or.ll
+++ b/test/CodeGen/X86/combine-or.ll
@@ -271,9 +271,8 @@ define <2 x i64> @test20(<2 x i64> %a, <2 x i64> %b) {
 define <2 x i64> @test21(<2 x i64> %a, <2 x i64> %b) {
 ; CHECK-LABEL: test21:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    orps %xmm1, %xmm0
-; CHECK-NEXT:    movq %xmm0, %xmm0
-; CHECK-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]
+; CHECK-NEXT:    por %xmm1, %xmm0
+; CHECK-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3,4,5,6,7]
 ; CHECK-NEXT:    retq
   %shuf1 = shufflevector <2 x i64> %a, <2 x i64> zeroinitializer, <2 x i32><i32 2, i32 0>
   %shuf2 = shufflevector <2 x i64> %b, <2 x i64> zeroinitializer, <2 x i32><i32 2, i32 0>
diff --git a/test/CodeGen/X86/vector-shuffle-128-v2.ll b/test/CodeGen/X86/vector-shuffle-128-v2.ll
index 9affee91700..cc7ae1f5706 100644
--- a/test/CodeGen/X86/vector-shuffle-128-v2.ll
+++ b/test/CodeGen/X86/vector-shuffle-128-v2.ll
@@ -667,14 +667,12 @@ define <2 x i64> @shuffle_v2i64_0z(<2 x i64> %a) {
 define <2 x i64> @shuffle_v2i64_1z(<2 x i64> %a) {
 ; SSE-LABEL: shuffle_v2i64_1z:
 ; SSE:       # BB#0:
-; SSE-NEXT:    pxor %xmm1, %xmm1
-; SSE-NEXT:    punpckhqdq {{.*#+}} xmm0 = xmm0[1],xmm1[1]
+; SSE-NEXT:    psrldq {{.*#+}} xmm0 = xmm0[8,9,10,11,12,13,14,15],zero,zero,zero,zero,zero,zero,zero,zero
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: shuffle_v2i64_1z:
 ; AVX:       # BB#0:
-; AVX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; AVX-NEXT:    vpunpckhqdq {{.*#+}} xmm0 = xmm0[1],xmm1[1]
+; AVX-NEXT:    vpsrldq {{.*#+}} xmm0 = xmm0[8,9,10,11,12,13,14,15],zero,zero,zero,zero,zero,zero,zero,zero
 ; AVX-NEXT:    retq
   %shuffle = shufflevector <2 x i64> %a, <2 x i64> zeroinitializer, <2 x i32> <i32 1, i32 3>
   ret <2 x i64> %shuffle
@@ -683,14 +681,12 @@ define <2 x i64> @shuffle_v2i64_1z(<2 x i64> %a) {
 define <2 x i64> @shuffle_v2i64_z0(<2 x i64> %a) {
 ; SSE-LABEL: shuffle_v2i64_z0:
 ; SSE:       # BB#0:
-; SSE-NEXT:    movq %xmm0, %xmm0
-; SSE-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]
+; SSE-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3,4,5,6,7]
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: shuffle_v2i64_z0:
 ; AVX:       # BB#0:
-; AVX-NEXT:    vmovq %xmm0, %xmm0
-; AVX-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]
+; AVX-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3,4,5,6,7]
 ; AVX-NEXT:    retq
   %shuffle = shufflevector <2 x i64> %a, <2 x i64> zeroinitializer, <2 x i32> <i32 2, i32 0>
   ret <2 x i64> %shuffle
diff --git a/test/CodeGen/X86/vector-shuffle-128-v4.ll b/test/CodeGen/X86/vector-shuffle-128-v4.ll
index 833b8225700..38fb3fb86a3 100644
--- a/test/CodeGen/X86/vector-shuffle-128-v4.ll
+++ b/test/CodeGen/X86/vector-shuffle-128-v4.ll
@@ -775,37 +775,27 @@ define <4 x i32> @shuffle_v4i32_zz4z(<4 x i32> %a) {
 define <4 x i32> @shuffle_v4i32_zuu4(<4 x i32> %a) {
 ; SSE2-LABEL: shuffle_v4i32_zuu4:
 ; SSE2:       # BB#0:
-; SSE2-NEXT:    xorps %xmm1, %xmm1
-; SSE2-NEXT:    movss %xmm0, %xmm1
-; SSE2-NEXT:    pshufd {{.*#+}} xmm0 = xmm1[1,1,1,0]
+; SSE2-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
 ; SSE2-NEXT:    retq
 ;
 ; SSE3-LABEL: shuffle_v4i32_zuu4:
 ; SSE3:       # BB#0:
-; SSE3-NEXT:    xorps %xmm1, %xmm1
-; SSE3-NEXT:    movss %xmm0, %xmm1
-; SSE3-NEXT:    pshufd {{.*#+}} xmm0 = xmm1[1,1,1,0]
+; SSE3-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
 ; SSE3-NEXT:    retq
 ;
 ; SSSE3-LABEL: shuffle_v4i32_zuu4:
 ; SSSE3:       # BB#0:
-; SSSE3-NEXT:    xorps %xmm1, %xmm1
-; SSSE3-NEXT:    movss %xmm0, %xmm1
-; SSSE3-NEXT:    pshufd {{.*#+}} xmm0 = xmm1[1,1,1,0]
+; SSSE3-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
 ; SSSE3-NEXT:    retq
 ;
 ; SSE41-LABEL: shuffle_v4i32_zuu4:
 ; SSE41:       # BB#0:
-; SSE41-NEXT:    xorps %xmm1, %xmm1
-; SSE41-NEXT:    blendps {{.*#+}} xmm1 = xmm0[0],xmm1[1,2,3]
-; SSE41-NEXT:    pshufd {{.*#+}} xmm0 = xmm1[1,1,1,0]
+; SSE41-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
 ; SSE41-NEXT:    retq
 ;
 ; AVX-LABEL: shuffle_v4i32_zuu4:
 ; AVX:       # BB#0:
-; AVX-NEXT:    vxorps %xmm1, %xmm1, %xmm1
-; AVX-NEXT:    vblendps {{.*#+}} xmm0 = xmm0[0],xmm1[1,2,3]
-; AVX-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[1,1,1,0]
+; AVX-NEXT:    vpslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
 ; AVX-NEXT:    retq
   %shuffle = shufflevector <4 x i32> zeroinitializer, <4 x i32> %a, <4 x i32> <i32 0, i32 undef, i32 undef, i32 4>
   ret <4 x i32> %shuffle
diff --git a/test/CodeGen/X86/vector-shuffle-128-v8.ll b/test/CodeGen/X86/vector-shuffle-128-v8.ll
index 59af434fd15..fc22a3e25e4 100644
--- a/test/CodeGen/X86/vector-shuffle-128-v8.ll
+++ b/test/CodeGen/X86/vector-shuffle-128-v8.ll
@@ -1429,15 +1429,13 @@ define <8 x i16> @shuffle_v8i16_zzzzz8zz(i16 %i) {
 define <8 x i16> @shuffle_v8i16_zuuzuuz8(i16 %i) {
 ; SSE-LABEL: shuffle_v8i16_zuuzuuz8:
 ; SSE:       # BB#0:
-; SSE-NEXT:    movzwl %di, %eax
-; SSE-NEXT:    movd %eax, %xmm0
+; SSE-NEXT:    movd %edi, %xmm0
 ; SSE-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1]
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: shuffle_v8i16_zuuzuuz8:
 ; AVX:       # BB#0:
-; AVX-NEXT:    movzwl %di, %eax
-; AVX-NEXT:    vmovd %eax, %xmm0
+; AVX-NEXT:    vmovd %edi, %xmm0
 ; AVX-NEXT:    vpslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1]
 ; AVX-NEXT:    retq
   %a = insertelement <8 x i16> undef, i16 %i, i32 0